CBS' 1967-8 Saturday morning schedule

 This was an era where Captain Kangaroo expanded to six days a week, so CBS could program a full 6 hour schedule, mostly with reruns.

For example, Jonny Quest was acquired from ABC to help fill out the lineup. The Road Runner Show was dropped down to the bottom of the schedule. It would expand to an hour the next year, moving to an earlier time as The Bugs Bunny-Road Runner Hour, with a portion of the open left intact.

Here's an ad:

This appeared in comic books, especially DC titles, and likely Gold Key, which held the license for the WB crew at the time, too.